HuTTON. — On New Zealand Neuroptera. 219 



Group DON ATA. 



The dragon-flies are well known to all, and are easily 

 recognised. The neuration of the wing is very complicated, 

 too much so to allow of intelligible description without a 

 diagram, and I must refer the student to Packard's " Guide to 

 the Study of Insects," or to a paper by Mr. "W. F. Kirby in 

 the twelfth volume of the " Transactions of the Zoological 

 Society of London," which can be seen in any museum 

 library. It will be sufficient here to point out that on the 

 anterior margin, about midway between the pterostigma and 

 the base, there is a short, thick, transverse nervule called the 

 " nodus," which stops the subcostal nervure. The nervules 

 between the nodus and the base of the wing are called 

 " ante-nodals " or " ante-cubitals," while those between the 

 nodus and the pterostigma are called " post-nodals " or 

 " post-cubitals." All the nervures which cross the wing 

 obliquely are called "sectors." That which starts from the 

 nodus is the " nodal sector," the one next behind it is the 

 " subnodal sector." Below the subcostal nervure comes the 

 "median nervure," and then the " submedian." The first 

 cross-nervule uniting the median with the submedian is the 

 " arculus," which sends off two sectors. The upper one of 

 these branches, a.nd that branch next to the median nervure 

 is called the " principal sector," while the posterior branch 

 forms the "median sector." The "triangle" is an easily 

 recognised area which lies just below the submedian nervure 

 and a little outside the arculus. 



The larva of the dragon-flies is aquatic and carnivorous, 

 and very unlike the imago. The pupa is active, and resembles 

 the larva, except for its rudimentary wings. Both larva and 

 pupa are sometimes called the nymph stage. In this stage 

 the lower lip is attached to an elongated " mentum," or mask, 

 which is articulated to the posterior lower portion of the 

 head ; and to this mask is articulated the large and fiat labium, 

 which differs in shape in the different tribes or families. In 

 the Lihellulina the labium is entire, while the large lateral 

 palpi are serrated on their inner edges. In the ^schnina it 

 is notched, and has narrow palpi with very strong spines. In 

 the Agrionina it is deeply cleft, and the palpi are slender, 

 with articulated spines. The nymphs of this tribe can also be 

 distinguished by having three elongated gills at the end of the 

 abdomen. 



Artificial Key to the New Zealand Genera. 

 Wings broad and rounded near their bases. 



Apices of the triangles of the fore wings directed 

 backwards; sectors of the arculus united at 

 their bases. 

 Sectors of the arculus petiolate . . . . Syiwpetnmi. 



Sectors of the arculus not petiolate . . . . Somatochlora. 



